Pneumatic trailer brake circuit with breakaway detection and method thereof

Patent metadata

Field	Value
Publication number	US-10328912-B2
Application number	US-201615222075-A
Country	US
Kind code	B2
Filing date	Jul 28, 2016
Priority date	Jul 28, 2016
Publication date	Jun 25, 2019
Grant date	Jun 25, 2019

Abstract

A method of detecting a leak in an air trailer brake circuit of a trailer includes providing a controller, a base valve, a first sensor, a second sensor, a leak control valve having a solenoid, a pneumatic fluid supply, a first brake output, and a second brake output. The method further includes supplying a first pressure to an inlet of the base valve and outputting a second pressure from an outlet of the base valve. The first pressure is detected with the first sensor and the second pressure is detected with the second sensor. The method also includes communicating the detected first pressure and the second pressure to the controller, and comparing a difference between first pressure and the second pressure to a threshold. A leak is detected in the air trailer brake circuit if the difference satisfies the threshold.

First claim

The invention claimed is:

1. A method of detecting a leak in an air trailer brake circuit of a trailer, comprising:
providing a controller, a base valve, a first sensor, a second sensor, a leak control valve having a solenoid, a pneumatic fluid supply, a first brake output, and a second brake output;
supplying a first pressure to an inlet of the base valve, where the first pressure is a hydraulic pressure;
outputting a second pressure from an outlet of the base valve, where the second pressure is a pneumatic pressure;
detecting the first pressure with the first sensor and the second pressure with the second sensor;
communicating the detected first pressure and the second pressure to the controller;
comparing a difference between first pressure and the second pressure to a threshold; and
detecting a leak in the air trailer brake circuit if the difference satisfies the threshold.

2. The method of claim 1 , further comprising energizing the solenoid of the leak control valve via the controller if the difference satisfies the threshold.

3. The method of claim 1 , further comprising actuating the leak control valve to a closed position if the difference satisfies the threshold.

4. The method of claim 1 , further comprising supplying pressurized fluid from the pneumatic fluid supply to the leak control valve.

5. The method of claim 1 , further comprising supplying a third pressure to a second inlet of the base valve from the pneumatic fluid supply, where the third pressure is a pneumatic pressure.

6. The method of claim 1 , further comprising determining the difference by first multiplying the first pressure by a ratio, and then subtracting the second pressure therefrom.

7. The method of claim 1 , further comprising de-energizing the solenoid if the difference does not satisfy the threshold.

8. The method of claim 7 , further comprising fluidly coupling the pneumatic fluid supply to the first and second brake outlet if the leak detect valve is de-energized.

9. The method of claim 1 , further comprising blocking pneumatic fluid from the first and second brake outlets when the difference satisfies the threshold.

10. The method of claim 1 , further comprising applying a park brake of the trailer if the difference satisfies the threshold.

11. The method of claim 1 , further comprising disengaging a park brake of the trailer if the difference does not satisfy the threshold.

12. The method of claim 1 , further comprising fluidly coupling the leak control valve and the base valve in series when the difference does not satisfy the threshold.

13. The method of claim 1 , further comprising:
fluidly coupling the pneumatic fluid supply to the first brake output via the leak control valve; and
fluidly coupling the pneumatic fluid supply to the second brake output via the leak control valve and the base valve.

14. The method of claim 1 , further comprising stopping the detected leak between the base valve and the second brake output by energizing the solenoid of the leak control valve.

15. A braking system of a trailer, comprising:
a pressurized supply of pneumatic fluid and hydraulic fluid;
a base valve including an inlet and an outlet, where the inlet is fluidly coupled to the pressurized supply of hydraulic fluid;
a solenoid control valve including an inlet fluidly coupled to the pressurized supply of pneumatic fluid, the solenoid control valve operably controlled between an energized state and a de-energized state;
a brake output fluidly coupled to the outlet of the base valve;
a first sensor and a second sensor fluidly coupled to the base valve, the first sensor configured to detect a first pressure at the inlet of the base valve, and the second sensor configured to detect a second pressure at the outlet of the base valve;
wherein, the solenoid valve is operably controlled to its energized state when a difference between the first pressure and second pressure satisfies a threshold.

16. The braking system of claim 15 , wherein in the de-energized state the pressurized supply is fluidly coupled to the base valve and the brake output, and in the energized state the solenoid control valve fluidly de-couples the pressurized supply from the base valve and the brake output.

17. The braking system of claim 15 , further comprising a second brake output fluidly coupled to the solenoid control valve in the de-energized state.

18. The braking system of claim 17 , further comprising a park brake pneumatically controlled by the second brake output between a disengaged position and an engaged position, wherein in the de-energized state the park brake is in its disengaged position, and in the energized state the park brake is in its engaged position.

19. The braking system of claim 15 , further comprising a controller disposed in electrical communication with the first sensor, the second sensor, and the solenoid, the controller storing the threshold and a ratio, where the ratio is a function of the base valve;
wherein, the controller determines the difference by multiplying the first pressure by the ratio and then subtracting the second pressure therefrom;
wherein, the controller compares the difference to the threshold, and sends an electrical signal to the solenoid to control the solenoid valve between its energized and de-energized states.

20. A pneumatic braking system of a trailer towed by a work machine, comprising:
a pressurized supply providing pneumatic fluid;
a pilot line providing hydraulic fluid;
a base valve including a first inlet, a second inlet, and an outlet, where the first inlet is fluidly coupled to the pilot line;
a solenoid control valve including an inlet and an outlet, the inlet of the solenoid control valve fluidly coupled to the pressurized fluid supply, and the outlet being coupled to the second inlet of the base valve;
a first control line fluidly coupled to the outlet of the base valve;
a second control line fluidly coupled to the outlet of the solenoid control valve;
wherein, the solenoid control valve is operably controlled between an energized state and a de-energized state;
wherein, in the de-energized state the pressurized supply is fluidly coupled to the second inlet of the base valve and the second control line, and in the energized state the solenoid control valve fluidly de-couples the pressurized supply from the second inlet of the base valve and the second control line.

Assignees

• Deere & Co

Inventors

• Schick Troy E
• Mcmillen Brandon J
• Tagtow Jordan

Classifications

• B60T17/226

  using devices being responsive to the difference between the fluid pressions in conduits of multiple braking systems · CPC title

• B60T17/221

  Procedure or apparatus for checking or keeping in a correct functioning condition of brake systems (hydraulic pressure systems in general F15B19/00, F15B21/04; testing structures or apparatus G01M) · CPC title

• B60T15/028

  in hydraulic systems · CPC title

• B60T13/581 Primary

  both hydraulic and pneumatic · CPC title

• B60T15/027

  in pneumatic systems · CPC title